Food Science-Comparison of Anthocyanin Extraction Yield Using Sonication, Blending and Homogenization Methods and Different Solvents
Mentor:Harmit Singh, Associate Professor (Food Chemist) of Human Nutirtion and Food Science, California Polytechnic University, Pomona
Anthocyanins are natural pigments found in variety of red, blue or purple plants which are also recognized for their antioxidant activity. Replacing artificial colors with natural pigments in foods is challenging due to its low stability and high cost. Improving yields will help to lower the cost. Our project was to compare different conditions for the extraction of Anthocyanins (the major colored component in fruits) from frozen blueberries. The three extraction methods compared were sonication, commercial agitation and high shear homogenization. The extraction of anthocyanin was examined spectrophotometrically at 520nm. The blueberries were crushed then mixed with the solvents in the ratio of 1: 10( gram: ml) for fixed periods of time, filtered, dried and the yields were recorded by weight percentage. Data was collected using four different solvents: acidified methanol (0.02% v/v), acidified water (0.02% v/v), acidified ethanol (0.02% v/v) and distiller water. Results showed that the yields of all three extraction methods were less than 2% and homogenization gave higher yield with shorter time frame. Increasing the homogenization speed didn't necessarily increase the extraction yield which could be attributed to the increase in temperature that might cause degradation of anthocyanins. Acidified ethanol and acidified water were more efficient in extraction as compared to pure solvents. As a result, for future research reference that a temperature controlled extraction process with acidified solvents might increase the extraction yield.